1. Field of the Invention
The present invention relates to graphical interfaces for computer systems. More specifically, the present invention relates to a method and an apparatus for facilitating substitution of a graphical image with a line drawing version of the graphical image in a graphical display in order to reduce the time required to retrieve and display the graphical image.
2. Related Art
The recent success of the world wide web can largely be attributed to the ease with which visitors to web sites can navigate through web pages containing textual information interspersed with graphical images. Unfortunately, these graphical images are typically stored as large bitmaps that require a great deal of time to transfer across a low-bandwidth modem connection. This creates significant delays in loading web pages, which can greatly annoy visitors to web sites.
In order to remedy this problem, web site designers can reduce the size and number of graphical images that are displayed on a web site. Alternatively, they can do away with graphical images altogether. However, either of these options greatly reduces the visual impact of a web site, and can thereby detract from the experience of navigating through the web site.
Another way to reduce delays in loading web pages is to use a “thumbnail” of a graphical image in place of the graphical image. A thumbnail is a miniature version of the graphical image that can be “clicked on” with a pointing device, such as a mouse, in order to display the larger fill graphical image. However, thumbnails are small and difficult to view. They are also smaller than the full graphical image. Consequently, when a thumbnail is expanded, it often displaces textual information or other images in a web page.
Another way to reduce delays in loading web pages is to use a lower resolution version of a graphical image, which requires less time to retrieve across a network. However, a lower resolution version of the graphical image is not as pleasant to view as the original higher resolution version of the graphical image. Furthermore, many details of the graphical image are lost in converting to the lower resolution version.
What is needed is a method and an apparatus that reduces the amount of data that must be retrieved in order to display a graphical image in a web page without the disadvantages of using a thumbnail or a lower resolution version of the graphical image.